Process of producing 1.3-butyleneglycol.



UNITED STATES PATENT OFFICE.

KONBAD DELBRTTCK ANDKURT MEISENBURG, OF ELBERFELD GERMANY, ASSIGNORS TO FARIBENFABRIKEN VORM. FRIEDR. BAYER 8: 00.. 0F ELBERFELD, GERKANY, A

QORPORA'IION OF GERMANY.

riiocnss or PRODUCING ra-nurnnnncnrcor...

1,094,539, No Drawing.

Patented Apr. 28, 1914.

man Empire, residing at Elberfeld, Ger-,

many, have invented new and-useful Improvements in Processes of Producing 1.3- Butyleneglycol, of which the following is a specification.-

It is a wellknown fact that 'aceta-ldehyde can be condensed in aqueous solution to aldol and that Jaldol can be reduced with sodium or with aluminium amalgam to'1.3- butyleneglycol. In British Letters Patent No. 17259/11 a combination of the two processes is. described consisting in reducing with metal amalgams the crude aldehyde condensation product containing the aldol.

It has now been found that the reduction of the crude aldol product. obtained by con:

densation of an aqueous solution of acetaldehyde e. g. with potash, can be carried out advantageously by electrolysis. This new discovery was surprising, as combinations of the type e. g. diacetone-alcohol are very sensitive to acids or alkalis and as the electrolytical reduction is effected in an acid solution. Another advantage of the new process is, that unchanged acetaldehyde or para-aldehyde is recovered by reductionlas alcohol which then can be again oxidized to acetaldehyde.

In order to illustrate the new process more fully the following example is given, the' parts being by weight :-100 parts of acetaldehyde are slowly mixed while being cooled A solution of 2.5 parts of potash in 25'parts of water is then added at a temperature of 10 C. This solution is after havin been stirred at 10 C. for 14 hours, aci ulated with sulfuric acid (25 per cent.) and'finally made up with this acid to .7 50 parts. Itis then reduced electrolytically for 24 hours in the cathode part of a closed cell, neutralized with chalk, and the calcium sulfate is removed by filtration. The 1.3-butylene-glycol is obtained from t. e filtrate by fractionated distillation. The yield of glycol is more than 50 per cent. of the acct-aldehyde, and more than 30 per cent. of the aldehyde are recovered as alcohol.

V VVe' claim 1. Process forthe production of 1.3-buty leue-glycol, which process comprises reducing aldol by electrolysis and separating the 1.3-butylene-glyccl from the reaction mixture. substantially as described.

2. The process of producing 1.3-glyc0l (1.3-diol) which comprises the electrolytic reduction of aldol in acid media.

3. The process of producing 1.3-glycol (1.3-diols) which comprises the electrolytic reduction of aldols in dilute sulfuric acid solutions.

4. The described process of producing glycol which consists in electrolytically reducing aldolin a dilute sulfuric acid solution. neutralizin the cathode liquid. and separating there rom the glycol.

In testimonv whereof we have hereunto set our hands in the presence of two suhscribing witnesses.

KONRAD DELBRI'JCK. [L.s.]

KURT MEISENBURG. [L.S.]

- itnesses:

ALBERT NUFER,

MARGARET JOHNSON.

ion sation in Letters Patent Ne. "256%,53g,

It is hereby certified that in Letter Patent No 1,094,539,;gmntd April 28,

191%,- upon the application 0i Konrad Delbri'zck andKurt Meisenbi rg, of Elberfeld, I Germ any, for an improvement in Processes of P 'eclucing'1.3 Butyneglyc0l, an

f errofappears 'in'jshe printed specification requiring correetiones follows: Line 25,

fermula, for R CHOH-CH -GOH reed 0HOH- 05 6/012,- and that the aid Letters Patent be read with this correction therein that;- the .edme may conform to the'r'eeordof the case in the Patent Ofice'.

Signed and sealed this'23rd day of June, A. 1)., 1914.

' [SEAL] R. F. WHITEHEAD,

Acting Omnwiz'ssioner of Patents. 

